阅读说明：本技术 无集管板型热交换器 (Header-plate-free heat exchanger ) 是由 小室朗 大友聪 于 2019-03-22 设计创作，主要内容包括：在供高温气体流通的增压空气冷却器中,防止气体的流入侧处的基于热循环而产生的龟裂。在构成芯(3)的横截面方形的扁平管(2)的长边部(2b)的两端部突出设置形成角状的第一高缘部(2c),并从该第一高缘部(2c)起,经由平滑地弯曲的第一弯曲部(2g)、第二弯曲部(2h)而与第一低缘部(2d)连接。(In a charge air cooler through which high-temperature gas flows, cracks caused by thermal cycles are prevented from occurring on the inflow side of the gas. First high edge portions (2c) that form an angular shape are projected from both end portions of long side portions (2b) of a flat tube (2) having a square cross section that constitutes a core (3), and are connected to first low edge portions (2d) from the first high edge portions (2c) via first bent portions (2g) and second bent portions (2h) that are smoothly bent.)

1. A header-less plate heat exchanger is provided with:

a flat tube (2) having a bulging portion (1) with both end portions open and bulging in the thickness direction, and formed in a square cross section by a pair of short side portions (2a) facing each other and a pair of long side portions (2b) orthogonal to the pair of short side portions (2 a);

a core (3) formed by stacking a plurality of flat tubes (2) on the bulging portion (1);

A cylindrical housing (5) that covers and fits the outer periphery of the core (3); and

a box main body (8) connected to the outer case (5),

the first fluid (17) flows from an inlet (20) -side opening to an outlet (21) -side opening of each flat tube (2), the second fluid (18) flows on the outer surface side of the flat tube (2),

the header-less plate type heat exchanger is characterized in that,

the pair of long side portions (2b) of each flat tube (2) includes:

a first high edge part (2c) continuous from an end of the short side part (2 a);

a first low edge portion (2d) located closer to the outlet (21) than the first high edge portion (2c) and formed longer than the first high edge portion (2 c); and

a first intermediate portion (2e) connecting the first high edge portion (2c) and the first low edge portion (2d),

the first intermediate portion (2e) is formed by a first curved portion (2g) and a second curved portion (2h), the first curved portion (2g) being smoothly recessed from the end of the first high edge portion (2c) toward the outlet (21), and the second curved portion (2h) being temporarily recessed toward the outlet (21) at the end of the first curved portion (2g), rising toward the inlet (20), and being smoothly continuous with the end of the first low edge portion (2 d).

2. A header-less plate heat exchanger is provided with:

a flat tube (2) having a bulging portion (1) with both end portions open and bulging in the thickness direction, and formed in a square cross section by a pair of short side portions (2a) facing each other and a pair of long side portions (2b) orthogonal to the pair of short side portions (2 a);

a core (3) formed by stacking a plurality of flat tubes (2) on the bulging portion (1);

a cylindrical housing (5) that covers and fits the outer periphery of the core (3); and

a box main body (8) connected to the outer case (5),

the first fluid (17) flows from an inlet (20) -side opening to an outlet (21) -side opening of each flat tube (2), the second fluid (18) flows on the outer surface side of the flat tube (2),

the header-less plate type heat exchanger is characterized in that,

the pair of long side portions (2b) of each flat tube (2) includes:

a second high edge part (2j) continuous from an end of the short side part (2 a);

a second low edge portion (2k) located closer to the outlet (21) than the second high edge portion (2j) and formed longer than the second high edge portion (2 j); and

a second intermediate portion (2m) connecting the second high edge portion (2j) and the second low edge portion (2k),

the second intermediate portion (2m) has a third curved portion (2n), the third curved portion (2n) is temporarily and smoothly recessed from an end of the second high edge portion (2j) toward the outlet (21) side of the second low edge portion (2k) and then rises toward the inlet (20), and a tip of the third curved portion (2n) is connected to the second low edge portion (2 k).

3. The header-less plate-type heat exchanger according to claim 1 or 2,

the header-less plate heat exchanger includes:

an O-ring plate (4) having a short tube part (4a) covering and fitting the outer periphery of the end part of the core (3) and an L-shaped part (4b) formed upright from the short tube part (4a) in a cross-sectional L shape, and an end opening edge (4c) of the L-shaped part (4b) is formed in a ring shape;

a rectangular tubular housing (5) that covers the outer periphery of the fitting core (3) with the O-ring plate (4) therebetween; and

and a box main body (8) in which the tip of the flange (8a) is press-fitted into an annular groove (7) between the outer case (5) and the O-ring plate (4) via an O-ring (6).

Technical Field

The present invention relates to a header-less plate heat exchanger in which flat tubes each having a bulging portion formed by bulging an open end in a thickness direction are stacked in the thickness direction at the bulging portion to form a core, and an outer periphery of the core is fitted and covered with a casing.

Background

Patent document 1 proposes a header-less plate heat exchanger in which flat tubes having bulges at both ends of an opening end are stacked in a thickness direction to form a core, and a shell is fitted over the outer periphery of the core. The heat exchanger is provided with a simple structure which does not need a header plate which is necessary in the prior art by bulging the end portions of the flat tubes in the thickness direction.

High-temperature gas is guided from one tank to the other tank disposed at both ends of the core, and heat is exchanged between the high-temperature gas and the cooling water supplied to the outer peripheries of the flat tubes.

In this heat exchanger, it is known that, in the vicinity of the inlet port of the high-temperature gas, thermal stress is generated in each flat tube forming the core by the high-temperature gas, and the durability thereof is greatly affected.

Fig. 13 is a perspective view of a main portion of the conventional heat exchanger and a longitudinal sectional view showing a problem thereof. In this heat exchanger, a plurality of flat tubes 2 having bulging portions 1 at both open ends are stacked on the bulging portions 1 to form cores 3, the ends of the cores 3 are covered with O-ring plates 4, and outer shells 5 are fitted over the outer peripheries of the O-ring plates 4.

As shown in fig. (C), the end opening of the tank main body 8 is fitted into the annular groove 7 formed between the O-ring plate 4 and the outer case 5 via the O-ring 6, and the tank main body 8 is fastened and fixed to the outer case 5 by the caulking pieces 22 provided on the outer periphery of the outer case 5. In the figure, high-temperature gas is supplied to each flat tube 2 of the core 3 from above.

Disclosure of Invention

Problems to be solved by the invention

In such a heat exchanger, cracks 19 may be generated at the opening edges of the flat tubes 2 due to the influence of intermittent heat cycles of high-temperature gas on the inlet sides of the flat tubes 2 of the core 3 in the long-term use.

Therefore, an object of the present invention is to improve durability against heat cycles in the vicinity of the high-temperature gas inlet of each flat tube.

Means for solving the problems

The invention described in claim 1 is a header-plate-less heat exchanger including:

a flat tube 2 having a bulging portion 1 with both end portions open and bulging in a thickness direction, and formed in a square cross section by a pair of short side portions 2a facing each other and a pair of long side portions 2b orthogonal to the pair of short side portions 2 a;

a core 3 formed by stacking a plurality of flat tubes 2 on the bulging portion 1;

a cylindrical housing 5 for covering and fitting the outer periphery of the core 3; and

a box main body 8 connected to the outer case 5,

the first fluid 17 flows from the inlet 20-side opening to the outlet 21-side opening of each flat tube 2, the second fluid 18 flows on the outer surface side of the flat tube 2,

the header-less plate type heat exchanger is characterized in that,

the pair of long side portions 2b of each flat tube 2 includes:

A first high edge portion 2c continuous from an end of the short side portion 2 a;

a first low edge portion 2d located closer to the outlet 21 than the first high edge portion 2c and formed longer than the first high edge portion 2 c; and

a first intermediate portion 2e connecting the first high edge portion 2c and the first low edge portion 2d,

the first intermediate portion 2e is formed by a first curved portion 2g and a second curved portion 2h, the first curved portion 2g being smoothly recessed from the end of the first high edge portion 2c toward the outlet 21, and the second curved portion 2h being temporarily recessed toward the outlet 21 at the end of the first curved portion 2g, rising toward the inlet 20, and being smoothly continuous with the end of the first low edge portion 2 d.

The invention described in claim 2 is a header-plate-less heat exchanger including:

a flat tube 2 having a bulging portion 1 with both end portions open and bulging in a thickness direction, and formed in a square cross section by a pair of short side portions 2a facing each other and a pair of long side portions 2b orthogonal to the pair of short side portions 2 a;

a core 3 formed by stacking a plurality of flat tubes 2 on the bulging portion 1;

a cylindrical housing 5 for covering and fitting the outer periphery of the core 3; and

A box main body 8 connected to the outer case 5,

the first fluid 17 flows from the inlet 20-side opening to the outlet 21-side opening of each flat tube 2, the second fluid 18 flows on the outer surface side of the flat tube 2,

the header-less plate type heat exchanger is characterized in that,

the pair of long side portions 2b of each flat tube 2 includes:

a second high edge portion 2j continuous from an end of the short side portion 2 a;

a second low edge portion 2k located closer to the outlet 21 than the second high edge portion 2j and formed longer than the second high edge portion 2 j; and

a second intermediate portion 2m connecting the second high edge portion 2j and the second low edge portion 2k,

the second intermediate portion 2m has a third curved portion 2n, the third curved portion 2n is temporarily and smoothly recessed from an end of the second high edge portion 2j toward the outlet 21 side than the second low edge portion 2k and then rises toward the inlet 20 side, and a tip of the third curved portion 2n is connected to the second low edge portion 2 k.

The invention described in claim 3 is the header-plate-less heat exchanger according to any one of claim 1 and claim 2, wherein,

the header-less plate heat exchanger includes:

An O-ring plate 4 having a short cylindrical portion 4a for covering and fitting the outer periphery of the end portion of the core 3 and an L-shaped portion 4b formed upright from the short cylindrical portion 4a in a cross-sectional L-shape, and an end opening edge 4c of the L-shaped portion 4b being formed in a ring shape;

a rectangular cylindrical housing 5 covering the outer periphery of the fitting core 3 with the O-ring plate 4 interposed therebetween; and

the front end of the flange 8a of the tank main body 8 is press-fitted into an annular groove 7 between the outer case 5 and the O-ring plate 4 via an O-ring 6.

Effects of the invention

In the invention according to claim 1, the presence of two smooth curved portions, i.e., the first curved portion 2g and the second curved portion 2h, formed between the first high edge portion 2c and the first low edge portion 2d disperses thermal stress generated at the inlet-side end portion of the flat tube 2 to each portion, and the curved portions elastically deform to absorb a difference in thermal expansion, thereby relieving the thermal stress. As a result, durability against thermal cycling is improved.

In the invention according to claim 2, the second high edge portion 2j, the third bent portion 2n, and the second low edge portion 2k are connected by a smooth curve, so that thermal stress generated at the inlet-side end portion of the flat tube 2 is dispersed to each portion, and the third bent portion 2n elastically deforms to absorb a difference in thermal expansion, thereby relieving the thermal stress. As a result, durability against thermal cycling is improved.

Drawings

Fig. 1 is a principal part front view of a first embodiment of a core 3 used in the heat exchanger of the present invention.

Fig. 2 is a main part perspective view of the core 3.

Fig. 3 is an exploded perspective view of the flat tube 2 of the first embodiment.

Fig. 4 is a main part front view of a core 3 of a second embodiment of the present invention.

Fig. 5 is a main portion perspective view of the core 3.

Fig. 6 is an exploded perspective view of the flat tube 2 of the second embodiment.

Fig. 7 is a main part exploded perspective view of the core 3 in the second embodiment and an assembly view thereof.

Fig. 8 is an exploded perspective view of the heat exchanger.

Fig. 9 is an exploded perspective view of the heat exchanger.

Fig. 10 is a principal part front view showing a header-less plate type heat exchanger of the third embodiment.

Fig. 11 is a perspective view of a main part of the heat exchanger.

Fig. 12 is a front view showing the inside of the heat exchanger.

Fig. 13 is a main part perspective view and a main part explanatory view showing a problem in the conventional heat exchanger.

Detailed Description

Next, embodiments of the present invention will be described with reference to the drawings.

Fig. 1 and 2 are views of a main part of the first embodiment of the present invention, and are views on the inlet 20 (see fig. 9) side of the high-temperature gas as the first fluid 17. The structures of fig. 7, 8, and 9 can be applied to the structure of the heat exchanger. Fig. 3 is an exploded perspective view of the flat tube 2.

The core 3 of the heat exchanger is formed by stacking a plurality of flat tubes 2 in the thickness direction at both ends of the opening portion thereof, and each flat tube 2 has bulging portions 1 at both ends of the opening portion thereof. In this example, each flat tube 2 is formed to have a square cross section by a pair of short side portions 2a facing each other and a pair of long side portions 2b orthogonal to the pair of short side portions 2 a.

As shown in fig. 2 and 7, O-ring plates 4 are fitted over both ends of the core 3. The O-ring plate 4 includes a cylindrical short cylindrical portion 4a and an L-shaped portion 4b formed in an L-shaped cross section from the tip of the short cylindrical portion 4 a. An annular end opening edge 4c is formed at the front end edge of the L-shaped portion 4 b.

A housing 5 shown in fig. 2 and 8 is fitted over the outer periphery of the core 3 with an O-ring plate 4 interposed therebetween. The housing 5 is formed in a cylindrical shape. A pipe 16 for the inlet and outlet of the cooling water, which is the second fluid 18, is connected to the casing 5. Second fluid flow channels 24 (fig. 7) are formed on the outer surface sides of the flat tubes 2, and the second fluid (cooling water) 18 is supplied from the duct 16 of the casing 5 shown in fig. 8 to the second fluid flow channels 24. The contact portions of the respective members are fixed by brazing to each other.

Next, an annular groove 7 (fig. 2) is formed between the housing 5 fitted over the outer periphery of the O-ring plate 4 and the L-shaped portion 4b of the O-ring plate 4, and as shown in fig. 9, the flange portion 8a of the tank main body 8 is press-fitted into the annular groove 7 via the O-ring 6, and the outer periphery of the flange portion 8a of the tank main body 8 is fastened and fixed to the housing 5 by caulking.

In this example, a slit 11 is formed in an opening edge portion of the housing 5, and an end edge side of the slit 11 is bent to form a caulking claw 22 (see fig. 13). The present invention is not limited to the rivet claw shown in fig. 13, and a claw portion not shown may be provided intermittently protruding from the opening edge of the outer case, and this claw portion may be used as a rivet claw bent in an L-shape toward the box main body 8.

Preferably, inner fins are inserted into the flat tubes 2. Further, a first fluid flow path 25 (fig. 7) is formed on the inner surface side of each flat tube 2, and the first fluid (high-temperature gas) 17 flows into the first fluid flow path 25 and the second fluid (cooling water) 18 flows on the outer surface side. Heat is exchanged between the first fluid (high-temperature gas) 17 on the inner surface side and the second fluid (cooling water) 18 on the outer surface side of the flat tube 2.

That is, in fig. 9, the cooling water as the second fluid 18 is supplied from the inlet-side duct 16 to the outer surface side of each flat tube 2, and is guided to the outlet-side duct 16. The first fluid 17, i.e., the high-temperature gas, flows in from an inlet 20 of the tank main body 8 on the inlet side, and flows out from an outlet 21 of the tank main body 8 on the outlet side.

Here, the present invention is characterized by the shape of each flat tube 2 constituting the core of the heat exchanger and the opening on the inlet 20 side of the first fluid 17 (see fig. 9). That is, the flat tube 2 of the present invention differs from the conventional flat tube in that a heat stress dispersion portion is formed on both short side portions 2a sides of a pair of long side portions 2b of the flat tube 2 formed in a square cross section.

A specific structure of the opening of the flat tube 2 will be described. First high edge portions 2c of a mountain shape continuous from the end portions of the pair of long side portions 2b on the short side portion 2a side are projected in a horn shape. A first low edge portion 2d is formed, and the first low edge portion 2d is located closer to the outlet 21 (fig. 9) side than the first high edge portion 2c of the long side portion 2b, and is formed to have a length longer than the first high edge portion 2 c. The first low edge portion 2d and the first high edge portion 2c are connected to each other by a first intermediate portion 2 e.

The first intermediate portion 2e is formed with a first curved portion 2g that smoothly dents from the end of the first high edge portion 2c toward the outlet 21 side.

A second bent portion 2h is formed between the first bent portion 2g and the first lower edge portion 2 d. The second curved portion 2h is temporarily recessed from the end of the first curved portion 2g toward the outlet 21 and then rises toward the inlet 20, and is smoothly continuous with the end of the first lower edge portion 2 d.

In fig. 3, a first high edge portion 2c, a first bent portion 2g, and a second bent portion 2h are formed on the short side portion 2a side of the long side portion 2b on the high-temperature gas inlet 20 side, and are continuous with both ends of the first low edge portion 2 d. The length of the first high edge portion 2c protruding in the chevron shape is preferably made narrower than the width of the L-shaped portion 4b of the O-ring plate 4.

As described above, it is understood that the formation of the inlet-side end portions of the pair of long side portions 2b of the flat tube 2 can prevent the cracks (see the crack 19 in fig. 13) that have conventionally occurred in the end portions of the long side portions 2 b.

As shown in fig. 3, the openings of the bulging portions 1 can be formed in a straight line on the outlet 21 side of each flat tube 2. This is because the first fluid 17, i.e., the high-temperature gas, is cooled by the second fluid 18, i.e., the cooling water, on the outlet 21 side to have a relatively low temperature, and therefore, the closer to the inlet 20 side, the less thermal stress is generated.

Next, fig. 4 and 5 are a front view and a perspective view of a main portion of a second embodiment of the heat exchanger according to the present invention, and fig. 6 is an exploded perspective view of the flat tube 2. This example differs from the above-described embodiments of fig. 1 and 2 in the shape of both end portions in the longitudinal direction of the long side portion 2b on the inlet 20 side of the flat tube 2.

In this example, a second high edge portion 2j continuing from the edge portion on the short side portion 2a side of the pair of long side portions 2b is formed. The second low edge portion 2k is formed longer than the second high edge portion 2j so as to be positioned closer to the outlet 21 of the high-temperature gas than the second high edge portion 2 j. The second high edge portion 2j and the second low edge portion 2k are smoothly continuous with each other via the second intermediate portion 2 m.

The second intermediate portion 2m has a third curved portion 2n, which is recessed from the end of the second high edge portion 2j to the outlet 21 side of the second low edge portion 2k, is temporarily and smoothly curved, and rises toward the inlet 20 side, and the tip of the third curved portion 2n is connected to the second low edge portion 2 k.

By forming in this manner, as in the first embodiment, thermal stress can be uniformly dispersed in each portion, and cracks in the end portions of the long side portions 2b of the flat tube 2 due to thermal stress can be effectively prevented.

The first and second embodiments are configured to rivet and fix the tank main body 8 and the outer case 5 with the O-ring 6 interposed therebetween.

Fig. 10 to 12 show a third embodiment of the heat exchanger according to the present invention.

As in the third embodiment, the outer case 5 can be fixed by brazing or welding to the tank main body 8. In this example, the flat tube 2 of the second embodiment is used, but the flat tube 2 of the first embodiment may be used.

In this case, as shown in fig. 10 to 11, it is preferable that the weld bead 5a abutting against the second high edge portion 2j of the flat tube 2 is provided on the side wall on the short side portion 2a side of the housing 5. As shown in fig. 12, the end of the box main body 8 also abuts the weld bead 5 a. In this state, brazing or welding is performed.

Industrial applicability

The present invention is applicable to heat exchangers in which various high-temperature gases flow, such as a charge air cooler and an exhaust gas recirculation device (EGR cooler).

Description of the reference numerals

1 bulge part

2 Flat tube

2a short side part

2b long side part

2c first high edge part

2d first lower edge part

2e first intermediate part

2g first bend

2h second bend

2j second high edge part

2k second lower edge part

2m second intermediate section

2n third bend

3 core

4O-shaped ring plate

4a short barrel part

4b L shaped part

4c end opening edge

5 outer cover

Bead 5a

6O-shaped ring

7 annular groove

8 case main body

8a flange part

11 slit

16 pipeline

17 first fluid (high temperature gas)

18 second fluid (cooling water)

19 cracking

20 inlet

21 outlet port

22 riveting claw

24 second fluid flow path

25 first fluid flow path.